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#![allow(clippy::uninlined_format_args)]
use std::iter::repeat;
fn square_is_lower_64(x: &u32) -> bool {
x * x < 64
}
#[allow(clippy::maybe_infinite_iter)]
#[deny(clippy::infinite_iter)]
fn infinite_iters() {
repeat(0_u8).collect::<Vec<_>>(); // infinite iter
(0..8_u32).take_while(square_is_lower_64).cycle().count(); // infinite iter
(0..8_u64).chain(0..).max(); // infinite iter
(0_usize..)
.chain([0usize, 1, 2].iter().cloned())
.skip_while(|x| *x != 42)
.min(); // infinite iter
(0..8_u32)
.rev()
.cycle()
.map(|x| x + 1_u32)
.for_each(|x| println!("{}", x)); // infinite iter
(0..3_u32).flat_map(|x| x..).sum::<u32>(); // infinite iter
(0_usize..).flat_map(|x| 0..x).product::<usize>(); // infinite iter
(0_u64..).filter(|x| x % 2 == 0).last(); // infinite iter
(0..42_u64).by_ref().last(); // not an infinite, because ranges are double-ended
(0..).next(); // iterator is not exhausted
}
#[deny(clippy::maybe_infinite_iter)]
fn potential_infinite_iters() {
(0..).zip((0..).take_while(square_is_lower_64)).count(); // maybe infinite iter
repeat(42).take_while(|x| *x == 42).chain(0..42).max(); // maybe infinite iter
(1..)
.scan(0, |state, x| {
*state += x;
Some(*state)
})
.min(); // maybe infinite iter
(0..).find(|x| *x == 24); // maybe infinite iter
(0..).position(|x| x == 24); // maybe infinite iter
(0..).any(|x| x == 24); // maybe infinite iter
(0..).all(|x| x == 24); // maybe infinite iter
(0..).zip(0..42).take_while(|&(x, _)| x != 42).count(); // not infinite
repeat(42).take_while(|x| *x == 42).next(); // iterator is not exhausted
}
fn main() {
infinite_iters();
potential_infinite_iters();
}
mod finite_collect {
use std::collections::HashSet;
struct C;
impl FromIterator<i32> for C {
fn from_iter<I: IntoIterator<Item = i32>>(iter: I) -> Self {
C
}
}
fn check_collect() {
let _: HashSet<i32> = (0..).collect(); // Infinite iter
// Some data structures don't collect infinitely, such as `ArrayVec`
let _: C = (0..).collect();
}
}
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